For the price go down again to 400 some serious things need to be happening. I don't see this coming, since we got a positive market.
Perhaps after the halving?
The big whales can push down the price briefly down to $400. But it will not last long, the value is there.
Big whales can do anything they want with the price. But they want to profit from it, so why dump a lot of coins to lower the price if they can sell them slower and profit more?
If the whale open a short position and sell the bitcoin price to lower level, they can make profit from the short position.